dir/include.html in IceWarp Web Mail 5.5.1, as used by Merak Mail Server 8.3.0r and VisNetic Mail Server version 8.3.0 build 1, allows remote attackers to include arbitrary local files via a null byte (%00) in the lang parameter, possibly due to a directory traversal vulnerability.
https://exchange.xforce.ibmcloud.com/vulnerabilities/23897
http://www.securityfocus.com/archive/1/420255/100/0/threaded
http://securitytracker.com/id?1015412